• 1954 – John Enders received a Nobel
prize in Medicine for growing polio
virus in human embryonic kidney
cells
• In 1998, James Thomson (University of Wisconsin-
Madison) isolated cells from the inner cell mass of the early
embryo, and developed the first human embryonic
stem cell lines.
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Totipotent Each cell can develop into a new individual
Cells from early (1-3 days) embryos
Pluripotent Cells can form any (over 200) cell types
Some cells of blastocyst (5 to 14 days)
Multipotent Cells differentiated, but can form a number of other
tissues
Fetal tissue, cord blood, and adult stem cells
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“CC” Carbon Copy
developing into all the cell types of the
body.
more di$cult to isolate, and purify.
Tens of thousands of frozen embryos
a r e r o u t i n e l y
destroyed when
treatment.
T h e s e s u r p l u s
embryos can be used
to produce stem cells.
R e g e n e r a t i v e
medica l research
egg is removed and
replaced with the nucleus
of a mature, "somatic
example).
this process, and no
womb.
The Ethical Problem
•
There is a risk of commercial exploitation of the human
participants.
• ESC will lead to reproductive cloning.
" Hematopoietic stem cells – forms all blood cell
types
(37°C), 0.075% Collagenase
After digestion with
(Mesenchimal Stem Cells)